The old Helensburgh station and tunnel have been unused since the early 1900s. Now it is overgrown with vegetation and gives you a sense of what this planet will be like when we are no longer around.
The tunnel was pitch black, and we didn’t dare go inside, however the info is that there are glow worms if you go in far enough. The info is also that you will be in ankle deep mud before you get that far!
Footing even outside is a little unstable, and it is best to avoid the area if it has been raining in the past week. The rail tracks retain water for quite a few days.